I've had ridiculously good luck with this antenna:
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I am also in an apartment, and I can't really put anything outside. I have these on a tripod in my living room, they are pretty small (the large one is a bit wide when fully extended, but most frequencies do not need full extension).
It takes a bit of tweaking and playing around, but I love it because once I get the length, orientation, direction right, it works better than almost any other antenna I have, besides the Yagi. They are also super cheap. By now, I pretty much know the length and orientation for each system I listen to by memory.
Use a dipole calculator like this:
West Mountain Radio - Antenna Calculator
to get an idea of the length to start at. Lock onto a frequency you want to listen to, and start the antenna at the length from the calculator, then make adjustments until you get the best signal. The optimal length is not always exactly what the calculator says, but its a good starting point.
Id recommend giving this a shot before spending more money on a different antenna, as this has really shocked me with how well it does. People dont understand how to tune it/adjust length for frequency, so they dont get as good results, but when you do, it is awesome.